Combined door lock and alarm

ABSTRACT

The invention contemplates an audible or other alarm feature integrated into a door-closure safety device such as a chain-bolt mechanism, wherein the bolt is selectively enterable into a slot in order that the chain may limit door movement, should conventional latch or lock mechanism be inoperative or inadequate. The alarm feature is so arranged as to operate before a would-be intruder has moved the door to the point of chain retention. Also, the alarm feature is retained in alarm condition, until reset only from the incise, i.e., from the protected region.

United States Patent I 72] Inventors Jerome L. Prinslty Wynnewood, Pm; Alan John Perfect, Willingboro, NJ. [21] App]. No. 44,157 [22] Filed June 8, 1970 [45] Patented June 15, 1971 [73] 'Assignee Wessel Hardware Corporation Philadelphia, Pa.

[54] COMBINED DOOR LOCK AND ALARM 19 Claims, 6 Drawing Figs. 52] us. CI 340/274, 1 16/14, ZOO/61.62 [51] Int. Cl. G08b 13/08 [50] Field of Search 340/274, 276; 116/14; ZOO/61.67, 61.68, 61.93

[56] References Cited UNITED STATES PATENTS 175,612 4/1876 Linnard 116/14 521,239 6/ 1894 Hoopes ZOO/61.68

Primary Examiner--.John W. Caldwell Assistant ExaminerScott F. Partridge Attorney-Sandoe, Hopgood and Calimafde ABSTRACT: The invention contemplates an audible or other alarm feature integrated into a door-closure safety device such as a chain-bolt'mechanism, wherein the bolt is selectively enterable into a slot in order that the chain may limit door movement, should conventional latch or lock mechanism be inoperative or inadequate. The alarm feature is so arranged as to operate before a would-be intruder has moved the door to the point of chain retention. Also, the alarm feature is retained in alarm condition, until reset only from the incise, i.e., from the protected region.

This invention relates to door-closure safety devices and in particular to those of the chain-bolt variety, and incorporates additional security features for such devices.

Lock mechanisms incorporated with conventional bolt-andstrike action have been and will remain the primary means of controlled access to a doorway, but these are all subject to tampering, picking, and other unauthorized access, requiring varying degrees of sophistication in accordance with the sophistication of the basic mechanism. As a common means of added security, chain-bolt mechanisms provide further protection, the bolt being one end of a chain which blocks the door opening, once the bolt is engaged in its slide track. Ordinarily, a would-be intruder will not know that the chain-bolt feature is to challenge him, until he has first been able to pick or force the conventional lock or latch mechanism which holds the door to its strike, in closed position. Having picked the lock or latch, he must of course try the door, to see if it will open, thus at least partially moving the door away from its strike-retained position. He will encounter the chain-bolt barrier only after such small movement, and so he must decide either to abandon his entry or to face the time required to destroy, disable or dislodge the chain lock.

It is an object of this invention to provide an alarm device operative in response to an unauthorized attempted entry into a chain-bolted door system of the character indicated.

Another object is to meet the above object with a device which, once actuated, remains actuated until the chain-bolt is actuated to its safety position, by access only from within the protected region; in other words, it is an object to deny the intruder any opportunity to disable the alarm, once triggered by his initial movement of the door.

A specific object is to meet the foregoing objects with electrically operated audible or other alarm means.

Ageneral object is to meet the stated objects with basically simple mechanism, which is capable of aesthetically acceptable adaptation to doorways, which is self-powered, and which lends itself to simple servicing operations.

Other objects and various further features of novelty and invention will be pointed out or will occur to those skilled in the art from a reading of the following specification in conjunction with the accompanying drawings. In,said drawings, which show, for illustrative purposes only, preferred and modified forms of the invention:

FIG. 1 is a view in elevation of a combined door lock and alarm of the invention, shown mounted upon a door and in the lock-set condition;

FIG. 2 is a perspective view of a chassis contained within the mechanism of FIG. 1;

FIG. 3 is a perspective view of the door mounted or open side of the housing for the chassis of FIG. 2;

FIG. 4 is an enlarged fragmentary view of coacting parts of the lock and alarm of the invention, for the lock-set condition, certain parts being shown schematically;

FIG. 5 is a view similar to FIG. 4 to illustrate the relation of parts, in an alarm condition; and

FIG. 6 is a simplified view in elevation, similar to FIG. 1, to illustrate a modification.

Briefly stated, the invention contemplates an audible or other alarm feature integrated into a door-closure safety device such as a chain-bolt mechanism, wherein the bolt is selectively enterable into a slot in order that the chain may limit door movement, should conventional latch or lock mechanism be inoperative or inadequate. The alarm feature is so arranged as to operate before a would-be intruder has moved the door to the point of chain retention. Also, the alarm feature is retained in alarm condition, until reset only from the inside, i.e., from the protected region.

Referring to FIG. 1 of the drawings, the invention is shown in application to a combined door lock and alarm device contained within housing structure 10 which may be a single plastic or metal casting or otherwise formed with mounting means such as lugs 11 for securing the same to the inner face of a door 12 for which the closure is to be additionally protected. The door in its locked condition fits into a frame or 5 jamb schematically indicated 13. The door may incorporate conventional lock or latch mechanism 14 operated by a knob 15 and having a'bolt 16 received in a strike 17, for the closed position shown. Key-operated means forming part of the mechanism 14 has been omitted as unnecessary to the present description.

The combined mechanism of the invention, namely, that contained within the housing 10, forms part of a chain-bolt system utilizing an elongated slot or guide 18. The slot 18 may be stamped or otherwise cut out of the material of housing 10 and includes an enlarged opening 19 at its end remote from the jamb I3, whereby the enlarged tail of a slide bolt 20 may be removably entered into the slot or guideLl B. Bolt 20 is carried at the free end of a chain 21, the other end of which is fixed to a suitable bracket fixture or the like 22, shown mounted near the jamb and upon the door frame. The particular fixture 22 which is shown incorporates an enlarged opening 23 into which the tail of bolt 20 may be received when the chain-bolt is not in the lock-set condition.

For the relation of parts shown in FIG. 1, the chain-bolt20 is in the lock-set condition wherein the conventional latch or lock mechanism 14 holds the door closed to the strike 17, and the bolt 20 is at an intermediate position along the length of the guide means or slot 18. In this condition, no alarm is sounded and no alarm will be sounded, in the absence of attempted forced entry by an outside intruder. If there has been no such attempted intrusion, the door is unlocked by sliding the bolt 20 all the way to the right to the access enlargement 19 so that the chain-guard feature is disconnected, and again no alarm condition is set off.

In accordance with the invention, the alarm condition is actuated only when the slide bolt 20 is moved to the region of guide means 18 which is adjacent the jamb end, i.e., to the region generally to the left of position of bolt 20 in FIG. 1. In the source of such movement, the tail of the bolt 20 proceeds through a path of movement which interferes with and therefore actuates a pivoted or otherwise displaceable element such as a cam member 24 FIGS. 2, 4, and 5). As shown, the cam member 24 forms part of a movable electrical contact based upon a single compliant and electrically conductive ribbon member 25. p

The compliant member 25 is shown fixedly anchored or referenced at one end 26 to an upstanding projection 27 forming part of the chassis 28 contained within housing 10. Cam member 24 is preferably of suitable molded plastic for purposes of achieving quiet and smooth coaction with the tail of bolt 20, as the bolt 20 slides along its guide means 18; as shown, member 24 is suitably fixed or otherwise carried by an upwardly and laterally extending stretch 29 of the compliant member 25. Beyond the outer end of cam member 24, the compliant member 25 includes a downward bend 30 which in a wide loop doubles back beneath the cam member 24, with a free end 31 which is in substantial clearance relation with the underside of cam member 24.

Preferably, the upper surface of cam member 24 is characterized by a first stretch 32 which in the normal or no-alarm condition (shown in FIG. 4) presents a gentle ramp to be engaged by the tail of bolt 20 for positions leftward of that shown in FIG. 1. The outer end of the upper surface of cam member 24 is characterized by a down slope 33, i.e., portion 33 slopes downward with respect to the stretch 32. Thus, in the course of movement of bolt 20 from the no-alarm condition represented by FIG. 4, to the alarm condition represented by FIG. 5, the tail of bolt 20 moves cam member 24 downwardly against the compliant reaction of increased bending at 34, with resultant depression or increased down slope of the outer cam region 33 ultimately engaged by bolt 20. In this outer position, representing the alarm condition, it will be noted that the surface 33 and the axis of guide means 18 diverge outwardly. There thus can be no tendency of the bolt 20 to return to the right (i.e., to the no-alarm position), regardless of the amount of vibration to which the door, the chain or other parts of the mechanism may be subjected by the would-be intruder.

In accordance with the invention, the doubled-back portion 30 of the compliant member 25 forms an electrical contact element which determines the open or closed condition of an electrical circuit for initiating an audible or other alarm. In FIG. 4, a dry battery 36 powers the alarm circuit and includes two upwardly facing terminals 37, 38. Terminal 38 is grounded, as indicated at 39..The alarmdevice is symbolized by a coil 40 in series with the ground connection and with the conductive compliant member 25. Preferably, the displacement of cam member 24, as a result of bolt movement from the FIG. 4 to the FIG. position, is of such extent as to assure adequate wipe of the doubled end or contact 30 at the battery terminal 37. The degree of this wipe is suggested in FIGS. 4 and 5 by the difference in clearance between the end 31 and the inside of cam member 24, for the different positions shown in these two FIGS. Serrations are shown formed in the stretch 32 of cam member 24, in the region in which it is engageable by chain bolt 20; thus, if the alarm circuit should be completed before bolt 20 rides over to surface 33, the serrations will serve to hold" the alarm, even in the presence of sound vibrations generated by the alarm.

In accordance with a further feature of the invention, assembly and reliability of the device of the invention are enhanced by embodying them in a two-part frame. The basic housing forms one of the parts (FIG. 3); the chassis 28 forms the other (FIG. 2). The housing 10 is shown as generally rectangularly prismatic and'having an open side which is applied against the face of the door 12 when mounted thereto. The chassis 28 is received within this open side of housing 10 and is secured in assembled relation by suitable screws or bolts (not shown) passing through openings 41, 42, 43, aligned with tapped bosses 41', 42', 43"which may be cast integrally within the housing, as clearly seen in FIG. 3.

The chassis 28 is preferably made of electrically insulating material, such as a suitable injection-molded plastic. The integral projection 27 for anchorage of compliant member 25 has already been identified. Other projections include an arcuate flange 44 defining means for retaining an electrically driven sound generator, buzzer or other alarm means 45. Such a device need merely be axially inserted and frictionally held in the socket defined at 44, with suitable electrical connection in series with compliant member 25, as already described. For the device 45 shown, sound generation is developed by axial displacement of a diaphragm 45' withina central opening in the shell 45 shown. This opening is preferably in register with a suitably foraminated region 46 in the housing 10, to allow for adequate sound propagation external to the housing 10. For a buzzer 45 which is preassembled in its own conductive shell, as shown, such shell may be one of the electrical terminals of the buzzer, so that only one lead wire need be involved in making circuit connections; thus, such wire may be connected to the spring ribbon 25, and for the case of a conductive metal housing 10, reliance can be placed on clamp action at 42, 43 to establish the ground connection, it being understood that bosses 42, 43' are so sized relative to the axial extent of the buzzer 45 that clamp action (and, hence, good electrical grounding contact) is assured.

Stop projections'47, 48 also form part of the chassis 28. Stop 47 is poised to limit upward movement of the compliant member 25, thus providing a resilient preload against downward deflecting actuation by bolt 20. The stop 48 is poised in clearance relation below the outer end of member 25-so as to prevent damage to member 25, as by unauthorized tampering via the slot 18. The stop projections 47, 48 are preferably of axial extent to seat and position the chassis 28 with respect to the inner wall of housing 10 when the chassis is secured at4I,42,43.

To complete the description of chassis 28, it is shown in FIG. 2 with integral upstanding parallel guide members 50, 51 for locating engagement with opposed longitudinal edges of the battery 36. For the type of battery shown, i.e., a generally rectangularly prismatic battery, the adjacent flat face or base of the chassis 28 locates one large side face of the battery, and the adjacent inner wall of the housing 10 locates the opposite face of the battery.

In accordance with a feature of the invention, access to the battery for checking or for replacement is available via a side port in housing 10. This port is provided along the bottom edge, for the mounting configuration shown in FIG. 1. The port is defined between spaced parallel guide means 52, 53 (FIG. 3) on a guide alignment which is generally normal to the plane of the open side of the housing 10 and which is also generally normal to the axis of insertion of the battery 36. The port may be closed by a slide 54 having ears (as at 55, FIG. 2) received in guide means 52, 53. As shown, the plate 54 has an upstanding externally accessible lip or flange 56 for ease of access and, accordingly, the port for battery insertion extends slightly around the lower outer corner of the housing, as indicated at 57 in FIG. 3. It will be understood that when the slide 54 is fully inserted in its guide means 52, 53, the flange 56 thereof may be received inconspicuously within the port edge 57 and may thus appear to be flush with and aesthetically integrated into the smooth overall appearance of the housing 10.

To complete the description of the battery-positioning means, it should be noted that the grounding device 39 for the case of a metallic housing 10 may be integrally formed as part of a lug case within the open end carrier of the housing (FIG. 3). The battery is inserted through the bottom part, and only the terminal 38 is topped by the grounding lug 39. In this condition, the other terminal 37 is poised in alignment with the contact end 30. The slide closure 54 preferably includes a spring-loading element, such as an arched compliant member 59, carried by or forming part of the slide plate 54, and the unstressed distension of element 59 issuch as to interfere with the bottom of the battery 36 as plate 54 is guided by means 52, 53 into its closed position. When fully closed, spring 59 is depressed to resiliently load the battery against the grounding contact 39.

FIG. 6 illustrates a modification wherein the described features contained within the housing 10 of FIG. 1 are incorporated into a similar housing 10' which also serves as the mount or journal for the knob 15 and its associated spindle 60. The spindle alignment is of course selected so as not to interfere with above-described action of alarm-actuating parts, and the spindle alignment 60 registers with that of conventional lock mechanism 14, having a projecting bolt or latch 16. Other parts in FIG. 6 will be recognized for their similarity to those already described and therefore the same reference numerals are used, with primed notation.

FIG. 6 serves to illustrate an additional function achievable when combined with the latch mechanism 14'. Such latch mechanism is shown to include an additional knob, lever or other actuating device 61 which is externally accessible to determine whether or not the lock feature has been selected. The actuator 61 will be understood to symbolize additional incorporation of an electrical switch, schematically indicated at the dashed line 62 in FIG. 4. Switch 62 may be in series with the battery connection to coil 40 and the coordination will be understood to be such that when the lock device 61 is in the lock-set condition, the battery circuit to coil 40 is complete, subject to bolt actuation of the contact 30. On the other hand, when the control member 61 is not in the lock-set condition, as for example, when the door is to be openable by knob actuation from either side, the switch 62 is in the open condition and no amount of bolt actuation will set off the alarm. The utility. of this optional provision will be appreciated for the condition that the occupant of the protected area may wish to utilize the chain-bolt 20 merely to set the door in a slightly ajar condition and of source, when thus set, it is not desired to operate the alarm.

it will be seen that the invention amply meets the stated objects and that the described device is basically simpleand easy to service and maintain. The replaceable parts are assembled and retained merely by sliding insertion, as for the case of the battery 36 and for the base of the buzzer or other alarm device 45. The parts may be rugged and fashioned in full aesthetic harmony with other hardware applied to the particular door.

The invention has been shown in application to a door which swings from a right-edge hinge axis (in the sense of FlGS. l and 6), but this represents no limitation, in that the housing 11 is merely reversed, when installed to a door that is hinged from its left edge. In that event, of course, the chainbolt guide 18 is below the cam member 24 and the battery 36, but operation is exactly as already described. The only difference is that to replace the battery 36, removal of the slide closure 54 will drop the battery in the FIG. 1 arrangement but will leave the battery unmoved, in the reverse arrangement. in the latter event, battery removal is facilitated by entering the slide-bolt 20 in its guide 18 and sliding the same until cam 24 is actuated; such cam actuation elevates the battery to an extent l to disconnect the ground connection 39 (and thus not sound the alarm) and (2) to facilitate removal of the battery 36.

As a further feature of the invention, a snap-lock or keyoperated lock maybe incorporated in the connection of chain 21 to the anchor fixture 22. Such a connection is schematically indicated at 22' in FIG. 1. With such separable connection, it will be appreciated that an individual can leave via the door 12 and, with the chain-bolt 20 in a set" condition in its guide 18, he need only snap-engage the chain connection at 22' before closing the door to set the latch 16 at strike 17. If connection 22 is key operated, he may gain access via the key at 22', plus the key (not shown) for the standard lock-set l4; otherwise, he will have to have some other means of entering if he is not to set off his own alarm.

Although the invention has been described in connection with the preferred and modified forms shown, it will be understood that further modifications may be made without departing from the scope of the invention.

What we claim is:

l. A door-closure safety device for use with a chained slidebolt, comprising a unitary frame with means for securing the same to one of two relatively movable door and door-frame structures to be monitored for effectively closed position, said frame including elongated guide means for the guided captive sliding displacement of an inserted slide bolt on an alignment generally normal to adjacent openable edges of said structures, said guide means having a bolt-insertion opening remote from said openable edges and terminating at a stop end near said openable'edges, and electrically operated alarm means including a circuit comprising a battery and an alarm generator and circuit-closure means, said alarm means including a member normally resiliently urged out of circuit-closing position and having a cam surface normally in the path of movement of an inserted slide-bolt along said guide means at a location intermediate said opening and said stop end, said member being displaceable' into circuit-closing condition upon cammed actuation by said slide-bolt only for slide-bolt positions between said intermediate location and said stop end, and latch means operative upon said bolt' primarily at said stop end of slide-bolt movement to provide an action unique to the stop end to retain at said stop end a displaced condition of said member for slide-bolt movement to said stop end, whereby said alarm means is inoperative to generate an alarm indication when the inserted slide-bolt is in the region at and near the insertion location, and whereby said alarm means is operative to hold alarm-circuit closure when and as long as the inserted slide-bolt is in the region between said stop end and the location of initial circuit closure, and especially in the operative condition of said latch means.

2. A safety device according to claim 1, in which said latch means comprises a down-ramp formation in said member and operative upon said slide bolt substantially only at the stop end of said guide means.

3. A door-closure safety device for use with a chained slidebolt, comprising a unitary frame with means for securing the same to one of two relatively movable door and door-frame structures to be monitored for effectively closed position, said frame including elongated guide means for the guided captive sliding displacement of an inserted slide-bolt on an alignment generally normal to adjacent openable edges of said structures, said guide means having abolt-insertion opening remote from said openable edges and terminating at a stop end near said openable edges, and electrically operated alarm means including a circuit comprising a battery and an alarm generator and circuit-closure means, said alarm means including a member normally resiliently urged out of circuit-closing position and having a cam surface normally in the path of movement of an inserted slide-bolt along said guide means at a location intermediate said opening and said stop end, said member being displaceable into circuit-closing condition upon cammed actuation by said slide-bolt only for slide-bolt positions between said intermediate location and said stop end, and said bolt and cam surface being formed to maintain a displaced condition of said member for slide-bolt movement to said stop end, whereby said alarm means is inoperative to generate an alarm indication when the inserted slide-bolt is in the region at and near the insertion location, and whereby said alarm means is operative to hold alarm-circuit closure when and as long as the inserted slide-bolt is in the region between said stop end and the location of initial circuit closure, said cam surface portion of said member including an up ramp "in approach to but effectively terminating prior to slide-bolt limiting at said end and including a down ramp in the vicinity of slide-bolt limiting at said end, whereby resilient loading of said member retains the slide-bolt at said end should it be chain driven to said end.

4. A door-closure safety device according to claim 3, in which said frame includes an outer housing into which said securing means is embodied, said housing having an open side which is applied against the member to which the mounted frame is securable, and an electrical chassis carried within said housing and bodily removable through the open side of said housing.

5. A door-closure safety device according to claim 4, in which said member is carried by said chassis.

6. A door-closure safety device according to claim 4, in which said chassis includes means for the bodily removable support of a unit-handling buzzer.

7. A door-closure safety device according to claim 4, in which said chassis includes battery-support means comprising spaced parallel guide members for guided retention of a battery inserted along its longitudinal axis, said housing having a lateral port aligned with said axis and of size to permit battery insertion and removal without requiring frame dismounting.

8. A door-closure safety device according to claim 7, in which said axis is parallel to but offset from the plane of the open side of said housing, and a closure member carried by said housing for removably closing said port.

9. A door-closure safety device according to claim 8, in which said removable closure member is a plate, slidably guided by said housing on an insertion axis generally normal to the battery insertion axis and to the plane of the open side of said housing.

10. A door-closure safety device according to claim 9, in which said housing is electrically conductive and includes an integral battery-terminal-engaging grounding lug positioned in the path of movement of a terminal of an inserted battery.

11. A door-closure safety device according to claim 10, in which said removable closure plate includes resilient means engaging an inserted battery and'loading the inserted battery into pressured terminal contact at said grounding lug.

12. A door-closure safety device according to claim 3, and including knob-spindle journal means aligned in clearance with said alarm means. i

13. A door-closure safety device according to claim 3, and latch mechanism including a knob spindle journaled on an alignment through said frame and in clearance with said alarm means, said latch mechanism including externally actuable means for selectively dogging the same, and switch means operated by said externally actuable means and operatively associated with said circuit.

14. A door-closure safety device according to claim 13, in which said switch means is series connected with said circuit, the connection being such that said switch is closed for the dog-selected condition of said externally actuable means, and said switch is open for the selected condition in which said latch mechanism is not dogged.

15. A door-closure safety device according to claim 3, and including a slide-bolt, chain and door-frame anchoring device, said chain and anchoring device having removable locking engagement.

16. A door-closure safety device according to claim 15, in

' insulative.

which said last-mentioned locking engagement is key operated.

17. A door-closure safety device according to claim 15, in which said last-mentioned engagement is snap locking.

18. A door-closure safety device according to claim 3, in which said frame is electrically conductive and includes a fixed battery-grounding element contacting one pole of said battery, said member including a flexible conductive contact wiper element displaceable into and'out of resiliently loaded wiping contact with the other pole of said battery in accordance with displacement of said member.

19. A door-closure safety device according to claim 3; in which the cam surface portion of said member is electrically 

1. A door-closure safety device for use with a chained slidebolt, comprising a unitary frame with means for securing the same to one of two relatively movable door and door-frame structures to be monitored for effectively closed position, said frame including elongated guide means for the guided captive sliding displacement of an inserted slide bolt on an alignment generally normal to adjacent openable edges of said structures, said guide means having a bolt-insertion opening remote from said openable edges and terminating at a stop end near said openable edges, and electrically operated alarm means including a circuit comprising a battery and an alarm generator and circuit-closure means, said alarm means including a member normally resiliently urged out of circuit-closing position and having a cam surface normally in the path of movement of an inserted slide-bolt along said guide means at a location intermediate said opening and said stop end, said member being displaceable into circuit-closing condition upon cammed actuation by said slide-bolt only for slide-bolt positions between said intermediate location and said stop end, and latch means operative upon said bolt primarily at said stop end of slide-bolt movement to provide an action unique to the stop end to retain at said stop end a displaced condition of said member for slide-bolt movement to said stop end, whereby said alarm means is inoperative to generate an alarm indication when the inserted slide-bolt is in the region at and near the insertion location, and whereby said alarm means is operative to hold alarm-circuit closure when and as long as the inserted slide-bolt is in the region between said stop end and the location of initial circuit closure, and especially in the operative condition of said latch means.
 2. A safety device according to claim 1, in which said latch means comprises a down-ramp formation in said member and operative upon said slide bolt substantially only at the stop end of said guide means.
 3. A door-closure safety device for use with a chained slide-bolt, comprising a unitary frame with means for securing the same to one of two relatively movable door and door-frame structures to be monitored for effectively closed position, said frame including elongated guide means for the guided captive sliding displacement of an inserted slide-bolt on an alignment generally normal to adjacent openable edges of said structures, said guide means having a bolt-insertion opening remote from said openable edges and terminating at a stop end near said openable edges, and electrically operated alarm means including a circuit comprising a battery and an alarm generator and circuit-closure means, said alarm means including a member normally resiliently urged out of circuit-closing position and having a cam surface normally in the path of movement of an inserted slide-bolt along said guide means at a location intermediate said opening and said stop end, said member being displaceable into circuit-closing condition upon cammed actuation by said slide-bolt only for slide-bolt positions between said intermediate location and said stop end, and said bolt and cam surface being formed to maintain a displaced condition of said member for slide-bolt movement to said stop end, whereby said alarm means is inoperative to generate an alarm indication when the inserted slide-bolt is in the region at and near the insertion location, And whereby said alarm means is operative to hold alarm-circuit closure when and as long as the inserted slide-bolt is in the region between said stop end and the location of initial circuit closure, said cam surface portion of said member including an up ramp in approach to but effectively terminating prior to slide-bolt limiting at said end and including a down ramp in the vicinity of slide-bolt limiting at said end, whereby resilient loading of said member retains the slide-bolt at said end should it be chain driven to said end.
 4. A door-closure safety device according to claim 3, in which said frame includes an outer housing into which said securing means is embodied, said housing having an open side which is applied against the member to which the mounted frame is securable, and an electrical chassis carried within said housing and bodily removable through the open side of said housing.
 5. A door-closure safety device according to claim 4, in which said member is carried by said chassis.
 6. A door-closure safety device according to claim 4, in which said chassis includes means for the bodily removable support of a unit-handling buzzer.
 7. A door-closure safety device according to claim 4, in which said chassis includes battery-support means comprising spaced parallel guide members for guided retention of a battery inserted along its longitudinal axis, said housing having a lateral port aligned with said axis and of size to permit battery insertion and removal without requiring frame dismounting.
 8. A door-closure safety device according to claim 7, in which said axis is parallel to but offset from the plane of the open side of said housing, and a closure member carried by said housing for removably closing said port.
 9. A door-closure safety device according to claim 8, in which said removable closure member is a plate, slidably guided by said housing on an insertion axis generally normal to the battery insertion axis and to the plane of the open side of said housing.
 10. A door-closure safety device according to claim 9, in which said housing is electrically conductive and includes an integral battery-terminal-engaging grounding lug positioned in the path of movement of a terminal of an inserted battery.
 11. A door-closure safety device according to claim 10, in which said removable closure plate includes resilient means engaging an inserted battery and loading the inserted battery into pressured terminal contact at said grounding lug.
 12. A door-closure safety device according to claim 3, and including knob-spindle journal means aligned in clearance with said alarm means.
 13. A door-closure safety device according to claim 3, and latch mechanism including a knob spindle journaled on an alignment through said frame and in clearance with said alarm means, said latch mechanism including externally actuable means for selectively dogging the same, and switch means operated by said externally actuable means and operatively associated with said circuit.
 14. A door-closure safety device according to claim 13, in which said switch means is series connected with said circuit, the connection being such that said switch is closed for the dog-selected condition of said externally actuable means, and said switch is open for the selected condition in which said latch mechanism is not dogged.
 15. A door-closure safety device according to claim 3, and including a slide-bolt, chain and door-frame anchoring device, said chain and anchoring device having removable locking engagement.
 16. A door-closure safety device according to claim 15, in which said last-mentioned locking engagement is key operated.
 17. A door-closure safety device according to claim 15, in which said last-mentioned engagement is snap locking.
 18. A door-closure safety device according to claim 3, in which said frame is electrically conductive and includes a fixed battery-grounding element contacting one pole of said battery, said member including a flexibLe conductive contact wiper element displaceable into and out of resiliently loaded wiping contact with the other pole of said battery in accordance with displacement of said member.
 19. A door-closure safety device according to claim 3, in which the cam surface portion of said member is electrically insulative. 